Copper(I) nitrate complexes. Synthesis and crystal structure of [Cu-2(mu-DATU)(2)(DATU)(4)](NO3)(2) (DATU=N,N '-diallylthiourea)

Crystal complex [Cu-2(mu-DATU)(2)(DATU)(4)](NO3)(2) (DATU = N,N'-diallylthi ourea) is obtained by ac electrochemical synthesis on copper electrodes, an d its crystal structure is determined [CAD-4 diffractometer, rotating coppe r anode, space group C2/c, a = 28.824(3), b = 11.831(1), c = 18.238(2) Angs trom, beta = 101.777(5)degrees, Z = 8, R = 0.071 for 1672 reflections]. The ligand molecules are coordinated to the copper atoms solely through the su lfur atoms. The centrosymmetric Cu2S2 core is formed due to one (bridging) of the three independent DATU molecules. The copper(I) atoms have a slightl y distorted tetrahedral environment. The [Cu-2(DATU)(6)](2+) and NO3- ions are joined together by the short contacts of the N-H ... ONO2 type [N ... O 2.81(1)-2.94(1) Angstrom]. A comparative analysis of the ligand affinity t o the central atom is carried out for the copper(I) nitrate complexes.